1. Field of the Invention
The present invention is directed to a load controlled battery charging device structured to apply a charge to a rechargeable storage battery having any one of a wide range of voltage output capacities. The load controlled battery charging device utilizes a load bank disposed in series with a power supply and a rechargeable storage battery, wherein a charging current applied to the rechargeable storage battery is controlled via a substantially constant electrical current drawn by the load bank.
2. Description of the Related Art
As the number of portable electronic devices available for communication, entertainment, and even transportation become increasingly available, the interest in providing portable energy sources for such devices also increases. In particular, efficient, effective, and economical devices to renew or recharge such portable energy sources, for example, rechargeable storage batteries, are of utmost interest and importance today.
The devices presently available to recharge such “rechargeable” batteries are typically structured to control a charging voltage to be applied to the rechargeable storage battery. While these devices may be effective in recharging such batteries, they are also typically specialized devices and may only be utilized for a small range of rechargeable storage batteries having the same or similar voltage output capacities. For example, a charging device structured for use with a 12 volt DC or 24 volt DC storage battery, such as may be used in an automobile, truck, or marine vehicle, are not readily adaptable for use with smaller storage batteries, such as the “AAA”, “C”, or “D” type batteries utilized in many portable electronic devices, much less the rechargeable storage batteries utilized to power the smallest portable electronic devices such as cellular telephones, PDA's, and digital cameras, just to name a few.
Additionally, the devices presently available typically require a complex and expensive array of electronic components to provide an electrical charging circuit to convert a standard power input, such as a 110/220 volt alternating current supply which is readily available worldwide, to a specific charging output current and voltage which may be utilized to charge a rechargeable storage battery in a reasonable time without danger of “overcharging”, and irreparably damaging the storage battery, the portable electronic device in which it is installed, or both. The present devices generally incorporate a transformer to convert and control an input voltage, and thereby indirectly control a specific charging current output to a rechargeable storage battery. As such, transformers inherently limit the range of applicability of present devices relative to an output voltage of a specific rechargeable storage battery with which it may be utilized.
Thus, there exists a need for a battery charging device that may be utilized to charge rechargeable storage batteries having a wide range of output voltage capacities, such as the low voltages utilized to power the most delicate portable electronic devices to the high voltage output of the banks of rugged marine batteries utilized to operate high speed racing boats, and beyond. It would be beneficial for such a charging device to permit variable control of a charging current to be applied to a rechargeable storage battery to accommodate a wide range of output voltage capacities of such batteries. Further, it would be preferable for any such charging device to operate without a transformer to eliminate the output voltage range limitations inherent therein. More in particular, it would be helpful to provide a charging device which permits variable control of a charging current in an efficient, effective, and economical manner.